Evangelion for sure, but not only because of the Mecha, because of the message.
I'm hopelessly in love with Macross, every time I think about it my eyes fill with tears, it's such a strong anime, the greatest weapon is music.
I've also warmed up to Sousei no Aquarion and Aquarion EVOL. I just find the battle sequences to be excellent and the characters endearing.
Oh, and TTGL is just fun.